i want to hook into when the button gets pressed or when entity gets used by player , ex when player use searchlight or press electrical button

I believe the majority of that is client-side, not sent to the server. You can listen for key input via OnPlayerInput, but that's about it in many cases.

thanks for the reply @Wulf

Merged post

found button press

object OnButtonPress(PressButton button, BasePlayer player)
{
    Puts("OnButtonPress works!");
    return null;
}​

but thanks for answer on clientside stuff . drove me crasy trying to get searchlight not to be used by player .... guess if its not ment to be , then its just so .:D

Actually didn't even remember that hook existed. :P